[1] MRC, CLIN RES CTR, DIV CELL PATHOL, HARROW HA1 3UJ, MIDDLESEX, ENGLAND
[2] UNIV WASHINGTON, DEPT PATHOL, SEATTLE, WA 98105 USA
[3] UNIV WASHINGTON, CTR RES ORAL BIOL, SEATTLE, WA 98105 USA
[4] UNIV WASHINGTON, DEPT PERIODONTICS, SEATTLE, WA 98105 USA